The 5 current main personas used by the Wikidata team (under construction! may need refinement!) are

• an active editor on Wikidata
• an occasional Wikidata editor
• an active editor on a larger Wikipedia
• an active editor on a small Wikipedia
• a data (re-)user working for a small startup

In T159514#3279121, @Spinster wrote:

The 5 current main personas used by the Wikidata team (under construction! may need refinement!) are

• an active editor on Wikidata
• an occasional Wikidata editor
• an active editor on a larger Wikipedia
• an active editor on a small Wikipedia
• a data (re-)user working for a small startup

And when seeing this very helpful list, I think these are good starting points to think about documentation.
As personas for documentation, I would think about the following dimensions / characteristics:

• not experienced at all with data(bases) -> extremely experienced
• not experienced at all with any Wikimedia project but not Wikidata -> extremely experienced with 1 or more Wikimedia projects that are not Wikidata
• working for an organisation that is a (potential) data provider/donator, e.g. a GLAM

I really like those dimensions and characteristics. I would add that for each one, it's helpful to think about "what is the smallest nugget of information that they need" to "perform X task." and how might that group best learn (Is it audio? Video? Text? A tutorial with detailed diagrams? A 1 on 1 session? A group session?)

@Jan_Dittrich Is this something we can close?

Depends… I guess this is still relevant and unresolved as long as the target groups have not been defined somewhere, yet.